1. Field of the Invention
This invention relates to a system for indicating to a user the residual heat of the pan support grids for gas burners of domestic cooking appliances, such as cookers, gas hobs and the like. The system of this invention is of the type defined in the introduction to the accompanying main claim.
2. Description of the Related Art
Above the gas burners of domestic appliances it is known to generally position a usually metal element in the form of a grid, the purpose of which is to support the pan and maintain it in its correct position, in particular while it is being heated. The grid can be constructed such as to extend over all or part of the burners, or alternatively each individual burner can have its own grid. The grids are removable to enable the user to clean the hob on which the burners are situated. During the use of the cooking appliance the grid or grids attain very high temperatures, and after the gas has been turned off require a considerable time, which can vary from a few to several minutes, to cool to a temperature level such as not to cause burns if touched. This cooling time depends on various factors including the mass of the grid or grids and the maximum temperature attained by them.
From the aforegoing considerations there is an apparent need for indicating to the user, for example visually, whether the grid or grids still have such a high residual temperature as to be able to cause burns if touched.
The residual grid temperature can be easily indicated by positioning a temperature sensor on the grid or in proximity thereto so as to measure its temperature, and connecting this sensor to a warning light which remains lit until the grid temperature attains a low level such as to be able to be handled without danger.
Solutions are known in the state of the art for measuring the residual temperature, in particular for glass ceramic hobs, either with electric heating elements or with gas burners positioned below the glass ceramic hob.
DE29619581 U1 relates to an invention which uses a solution analogous to the aforesaid applied to glass ceramic hobs, to measure the residual heat of the glass ceramic plate of a hob with external exposed gas burners.
Those solutions which use temperature sensors to measure the temperature of a hob or of the grids have however various drawbacks, including the difficulty of finding a position for the sensor such that it is not damaged, or in particular rendered inoperative, when the grid is removed and/or when the grid support surface is to be cleaned, and also the cost of a sensor which has to operate at high temperature.
The solution based on the use of sensors is hence inadequate.